Evaluation of super napier (Pennisetum purpureum × P. glaucum) as ruminant fodder by In vitro and In situ methods

In India, the ruminant animal production faces challenges due to insufficient availability of feedstuffs and low-quality of forage crops. To address these issues, cultivating high-yielding, nutritious varieties like Super Napier (Pennisetum purpureum × P. glaucum) and conserving them is vital to sustain ruminant farming. Hence, an attempt was made to assess Super Napier (SN) hay as ruminant feeds tuff byin vitro and in situ methods. Initially, SN hay was subjected to rumen in vitro gas production (RIVGP) study, with cumulative gas production (GP) measured at various time intervals up to 96 h post incubation. Subsequently, in vitro true dry matter digestibility (IVTDMD) and neutral detergent fiber digestibility (NDFD) were determined using a modified two-stage in vitro technique. Further, SN hay was subjected to a 96 h ruminal incubation to evaluate dry matter (DM), crude protein (CP) and neutral detergent fiber (NDF) degradability using in situ method. The chemical analysis of SN hay revealed that it contains organic matter (OM) 86.9%, CP -9.96%, NDF -72.5% and acid detergent fibre (ADF)-47.0% on DM basis. In the rumen kinetics study, the potential gas production (D) was 57.0 mL, with the rate of gas production (c) 0.035 h^-1. The IVTDMD and NDFD of SN hay were 68.7% and 40.5%, respectively. The potential in situ degradability and degradation rate for DM, CP, and NDF of SN hay were 68.5 % at 0.049 h^-1, 73.0% at 0.048 h^-1 and 62.0% at 0.044 h^-1, respectively. Further, the estimated metabolizable energy (ME) of SN hay was 7.22 MJ/kg DM. Thus, SN hay with good amount of GP, in vitro DM and NDF digestibility and in situ DM, CP and NDF degradability can be considered as a good source of basal fodder feedstuff for ruminant production.